Bay gardeners have been warned to protect themselves from Legionnaires' disease this spring.
There have already been 15 cases of legionellosis or Legionnaires' disease - a serious illness that can require hospital treatment - reported in the Bay this year, according to Toi Te Ora Public Health.
Last year there were 25 total and 21 in 2015.
Infections are usually caused by inhaling dust from compost and potting mixes containing the bacteria that cause the disease.
Medical Officer of Health Dr Jim Miller said gardeners could take simple steps when working with compost or potting mix to reduce their risk of getting the disease.
"Take measures to avoid inhaling dust. It's a good idea to open potting mix by cutting rather than ripping the bag, and open the bag away from your face," he said.
"Water gardens gently using low pressure, and, where possible, avoid working in unventilated places such as closed sheds and greenhouses.
"When potting plants, gently wet the soil or compost first to reduce dust and wash your hands after handling."
Dr Miller recommended using a face mask, especially when other measures were not practical.
Legionnaires' disease was more common in older people, smokers and people with underlying lung disease and other long-term conditions such as diabetes.
Young, fit and healthy people were rarely affected. The disease does not spread from person to person.
Legionnaires' disease can vary in severity from a flu-like illness to severe pneumonia.
- muscle aches and pains
- shortness of breath
See your doctor if you develop these symptoms within two to 10 days of handling compost or potting mix.